Prevalence of abdominal aortic aneurysm and repair outcomes on the basis of patient sex: should the timing of intervention be the same?

Abstract

See related editorials on pages 314, 318, and 322.T he prevalence of abdominal aortic aneurysms (AAAs) has been reported to be higher in men than in women. Most prevalence studies (AAA diagnosed by means of autopsy, ultrasound screening, and hospital discharge data) demonstrated the percentage of AAAs diagnosed in women to be 19% to 34% and the percentage diagnosed in men to be 66% to 81%. [1][2][3][4][5] This rate appears to be reliably constant in many Western nations. No cause or causes for the dramatic difference in the prevalence of AAAs between the sexes has been identified.Risk-factor profiles appear to be similar for both sexes. Age, cigarette smoking, and family history are all reported to have high association with AAA formation. 5,6 Women are usually older than their male counterparts when they undergo AAA repair (Tables 1 and 2). 1,[6][7][8][9][10][11][12] Men have a higher association of ischemic coronary artery disease and peripheral aneurysms (usually femoral or popliteal in location), and women have a higher incidence of concomitant aortoiliac occlusive disease. 6 The decision of when to recommend repair of an AAA for women is debatable. The general consensus is that the rupture rate increases with increasing aortic diameter. The rupture rate increases dramatically as the aneurysm diameter approaches 5 cm. Generally, when the aneurysm attains this size, treatment is recommended for low-risk patients in the United States. Similarly, a 5.5-cm aneurysm diameter is used for this standard in the United Kingdom. Data concerning the optimal timing of repair have been generated primarily in men. Measurement of AAA diameter, combined with close analysis of the individual patient's surgical risk, has been used historically to make operative recommendations. The optimal timing of repair on the basis of aortic diameters for women has not been clearly defined. The risk-benefit analysis might be different for women. The UK Small Aneurysm Trial demonstrated a 3-fold increase in the incidence of rupture of an AAA when controlling for aneurysm size in women compared with men. 4 Therefore do normal aortas differ in size between men and women? A study designed to screen the size of abdominal aortas by using ultrasonography reported significant differences in normal aortic diameter between the sexes, as well as based on body mass indices and body surface area. 13 In this study a total of 122,272 men and 3450 women were screened. Normal aortic diameter differed between men and women by 0.14 cm (women having the smaller aortic diameter). 13 This finding is statistically significant, but the absolute size difference between men and women is small.Several studies that examined hospital data (prevalence of AAAs and subsequent surgical treatment) suggested that women are offered surgical repair of AAAs at an alarmingly lower rate than their male counterparts. 7,10,11 Unfortunately, these studies could not provide further data regarding the decision not to repair the AAA. Perhaps the women decided to forego therapy. Also po...

Evaluation of coronary artery disease and other risk factors in patients with abdominal aortic aneurysm

“…Individuals with ages ≥ 60 years are more affected by this disease. [6,13] The natural course of the aneurysm is progressive expansion and rupture. To prevent rupture formation and decrease the mortality risk, it is essential to operate on the patient at the proper time, and aneurysm diameter is an important factor for determining this time.…”

“…Cigarette smoking has been determined to be an important risk factor in many studies investigating the coexistence of AAA and CAD and the associated risk factors. [2,[4][5][6] Since cigarette smoking is the most easily modified parameter among risk factors, encouragement to quit smoking might result in a reduction in risk for both AAA and CAD.…”

“…An aortic diameter of >5 cm has been associated with an increase in the risk for rupture. [6] The prevalence of rupture-related mortality has been reported to be 40-50% among AAA patients who underwent surgical intervention and up to 90% in AAA patients who did not undergo surgery. [4,7] Generally, an abdominal aorta diameter of >5 cm is considered to be an indicator for surgery.…”

Abdominal Aortic Aneurysms: Changing Paradigms in Treatment

“…17 Depending on interpretation and resources this information may help determine when to treat patients with smaller AAA at an earlier stage. Further, it has been suggested that the threshold in women be even lower (e.g., 4.5 cm in diameter) based on women's relatively smaller aortic dimensions, which appear to play a role in their higher risk of rupture and its attendant mortality and in their 18 lower anatomical suitability for EVAR 14,18,19 While in the past there was "no disagreement about appropriate treatment for large AAAs in patients with unsuitable anatomic characteristics that preclude EVAR, these patients should have conventional open repair, which has been reported to have low morbidity and mortality rates 14 . The advancement of technology has steadily whittled away at these anatomic criteria and continues to push the safe and acceptable anatomical criteria further into what was once considered to be the experimental or anatomically unacceptable range.…”

Capsule Commentary on Olchanski et al., Abdominal Aortic Aneurysm Screening: How Many Life Years Lost from Underuse of the Medicare Screening Benefit?

“…3 The authors estimate the numbers indirectly from other available studies, and therefore the projected estimates may not be accurate in that population.…”